The present invention relates to an ultrasound system with an ultrasound generator and a resonator connected to the ultrasound generator for conducting ultrasound and supplying the ultrasound to a fluid medium.
Ultrasound systems are widely used for the generation of low-frequency high-power ultrasound, for example, to atomize flowable media such as dispersions, solvents, water, oils, emulsions, melts, acids, bases and other liquids. For this purpose, low-frequency high-power ultrasound with amplitudes of 1 to 350 μm, preferably 10 to 80 μm and for example 35 μm is generated by the aforementioned ultrasound systems and transmitted from the resonator to the flowable medium. Low frequency high-power ultrasound refers to ultrasound with an operating frequency of 15 to 2000 kHz, preferably 15 to 800 kHz and for example 25 kHz, and an acoustic power above 5 W, preferably 10 W to 20,000 W, and for example 200 W. For example, piezoelectric or magnetostrictive ultrasound generators are used to generate the ultrasound. The resonator is, for example, an acoustic transducer and a two-dimensional or curved plate oscillator or a tubular resonator.
When flowable media are exposed to ultrasound in open containers or vessels, the ultrasound resonator typically extends from above into the liquid to be treated. With this structure, the ultrasound generator is located in this case above the sample to be exposed to ultrasound. Under normal laboratory conditions with for example ceiling-mounted lamps installed above the workspace, the ultrasound system casts a shadow on the sample to be treated. This complicates working and reduces the possibilities for a visual assessment of the result attained with the exposure to ultrasound.
The term ultrasound usually refers to oscillations which are barely or not at all perceptible to the human ear. In addition, the acoustic perception can be additionally impeded by the recommended use of ear protection or sound absorbing enclosures, such as acrylic glass enclosures. It is therefore sometimes difficult to acoustically perceive the operating state of the ultrasound system. However, low-frequency high-power ultrasound produces hazardous conditions during operation, for example, through manual contact, or through formation of splashes or aerosols when immersing an already vibrating resonator in a liquid. Poor illumination of the resonator may make it difficult for the operator to recognize whether the resonator is already immersed in the medium. However, when an already vibrating resonator is immersed in the medium, the medium may shoot from its container due to the ultrasound vibration and endanger or even injure the operator.
It would therefore be desirable and advantageous to obviate prior art shortcomings and to provide an improved ultrasound system, which is safer to operate than conventional ultrasound systems.